The present invention generally relates to valves and more particularly relates to a pressure control valve for use in electrohydraulic brake systems.
WO 00/02755A which was published after the priority date of the present invention discloses a pressure control valve of this type which includes a valve member arranged in a valve housing and a sensor element for determining the fluid pressure that prevails in the valve housing. The fluid pressure is determined directly by the arrangement of the sensor element in the valve housing, to what end corresponding structural provisions are necessary which also affect the overall dimensions of the pressure control valve. Due to the relatively high operating pressure, a correspondingly expensive sensor system is generally required which is permanently exposed to high pressures.
From generic publication WO 96/33080A a brake system with an electronic brake pressure control is known which is equipped with an impact sound sensor by means of which the change-over behavior of several pressure control valves of the brake system is established for the approximate determination of the brake pressure that prevails in a brake pressure generator and/or in several wheel brakes. To this end, the impact sound sensor is respectively arranged at a location of the valve housing of a pressure control valve such that the impact sound which is caused when a valve tappet or a valve head gets into contact on the valve housing is transmitted undamped to the impact sound sensor. Consequently, the impact sound sensor exclusively senses the vibrations which are transmitted onto the valve housing by the mechanical impulse of the moved valve components.
DE 198 30 464 A1 discloses a pressure control valve of this type which includes a valve member arranged in a valve housing and a sensor element for determining the fluid pressure that prevails in the valve housing. The fluid pressure is determined directly by the arrangement of the sensor element in the valve housing, to what end corresponding structural provisions are necessary which also affect the overall dimensions of the pressure control valve. Due to the relatively high operating pressure, a correspondingly expensive sensor system is generally required which is permanently exposed to high pressures.
In view of the above, an object of the present invention is to configure a pressure control valve of the type initially referred to in such a way that a low-cost determination of the hydraulic pressure that acts in the pressure control valve is ensured by entailing relatively low structural and functional efforts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a basic circuit diagram of the sensor assembly that is essential to the present invention.
FIG. 2 shows an embodiment for the design, of a sensor element for the assembly presented in FIG. 1.